Method and apparatus for reducing noise from a mobile telephone and for protecting the privacy of a mobile telephone user

Abstract

A method for reducing noise for a mobile telephone uses two boom microphones to create a processed voice signal with reduced noise content. A voice signal is received from a first microphone positioned near a user's mouth. A noise signal is received from a second microphone positioned at a distance from the user's mouth. A microprocessor cancels the noise signal from the voice signal and outputs the processed voice signal with reduced noise content. Another embodiment protects the privacy of a user of a mobile telephone by creating an acoustic signal from a sensed user's voice signal, which acoustic signal is an inverse of the user's voice signal. This inverse acoustic signal prevents any intelligible voice from reaching any bystanders.

What is claimed is:  
     
         1 . A method for reducing noise that is transmitted over a mobile telephone comprising: 
 sensing a voice signal of a mobile telephone user with a first microphone;    sensing a noise signal of the ambient noise around the mobile telephone with a second microphone; and    canceling the noise signal from the voice signal and forwarding over the mobile telephone a processed voice signal with reduced noise content.    
     
     
         2 . The method according to  claim 1 , wherein the first microphone is positioned near a mouth of the mobile telephone user.  
     
     
         3 . The method according to  claim 1 , wherein the second microphone is positioned at a distance from a mouth of the mobile telephone user relative to a position of the first microphone.  
     
     
         4 . The method according to  claim 1 , wherein the canceling includes creating an inverted noise signal from the sensed noise signal and adding the inverted noise signal to the sensed voice signal to create the processed voice signal.  
     
     
         5 . An apparatus for reducing ambient noise for a mobile telephone comprising: 
 a first microphone to sense a voice signal of a mobile telephone user;    a second microphone to sense a noise signal of the ambient noise around the mobile telephone; and    a processor coupled to the first and second microphones to cancel the sensed noise signal from the sensed voice signal and to output a processed voice signal with reduced noise content.    
     
     
         6 . The apparatus according to  claim 5 , wherein the first microphone is positioned near a mouth of the mobile telephone user.  
     
     
         7 . The apparatus according to  claim 5 , wherein the second microphone is positioned at a distance from the mouth of the mobile telephone user relative to the first microphone.  
     
     
         8 . The apparatus according to  claim 5 , wherein the processor creates an inverted noise signal from the sensed noise signal and adds the inverted noise signal to the sensed voice signal to create the processed voice signal.  
     
     
         9 . A method for protecting a privacy of a mobile telephone user comprising: 
 sensing a voice signal of the mobile telephone user;    creating an acoustic signal inverse to the sensed voice signal; and    outputting the inverse acoustic signal.    
     
     
         10 . The method according to  claim 9 , wherein a microphone positioned near a mouth of the mobile telephone user senses the voice signal.  
     
     
         11 . The method according to  claim 9 , wherein the inverse acoustic signal is output by an acoustic transmitter positioned near the mobile telephone user.  
     
     
         12 . An apparatus for protecting a privacy of a mobile telephone user comprising: 
 a microphone to sense a voice signal of the mobile telephone user;    a processor coupled to the microphone to create a signal inverse to the sensed voice signal; and    an acoustic transmitter controlled by the processor and outputting an acoustic signal inverse to the sensed voice signal.    
     
     
         13 . The apparatus according to  claim 12 , wherein the microphone is positioned near a mouth of the mobile telephone user.  
     
     
         14 . The apparatus according to  claim 12 , wherein the acoustic transmitter is positioned near the mobile telephone user.  
     
     
         15 . The apparatus according to  claim 12 , where the acoustic transmitter is an acoustic speaker.  
     
     
         16 . A method for reducing noise that is transmitted over a mobile telephone and for protecting a privacy of a mobile telephone user comprising: 
 sensing a voice signal with a first microphone;    sensing a noise signal with a second microphone;    canceling the noise signal from the voice signal and outputting a processed voice signal with reduced noise content;    creating a signal inverse to the voice signal sensed by the first microphone; and    outputting an inverse acoustic signal through an acoustic transmitter positioned near the mobile telephone.    
     
     
         17 . The method according to  claim 16 , wherein the first microphone is positioned near a mouth of the mobile telephone user.  
     
     
         18 . The method according to  claim 16 , wherein the second microphone is positioned at a distance from a mouth of the mobile telephone user relative to a position of the first microphone.  
     
     
         19 . The method according to  claim 16 , wherein the canceling includes creating an inverted noise signal from the sensed noise signal and adding the inverted noise signal to the sensed voice signal to create the processed voice signal.  
     
     
         20 . The method according to  claim 16 , wherein the inverse acoustic signal is output by a speaker positioned near the mobile telephone user.  
     
     
         21 . An apparatus for reducing noise for a mobile telephone and for protecting a privacy of a mobile telephone user comprising: 
 a first microphone to sense a voice signal;    a second microphone to sense a noise signal;    a processor coupled to the first and second microphones to cancel the noise signal from the voice signal, to output a processed voice signal with reduced noise content, and to create an inverse signal that is inverse to the sensed voice signal; and    an acoustic transmitter coupled to the processor to output an acoustic signal inverse to the voice signal.    
     
     
         22 . The apparatus according to  claim 21 , wherein the first microphone is positioned near a mouth of the mobile telephone user.  
     
     
         23 . The apparatus according to  claim 21 , wherein the second microphone is positioned at a distance from the mouth of the mobile telephone user relative to the first microphone.  
     
     
         24 . The apparatus according to  claim 21 , wherein the processor creates an inverted noise signal from the sensed noise signal and adds the inverted noise signal to the sensed voice signal to create the processed voice signal.  
     
     
         25 . A portable telephone comprising: 
 a voice microphone to receive a voice signal;    an ambient noise microphone to receive an ambient noise signal;    a processor coupled to the voice microphone and the ambient noise microphone to cancel the ambient noise signal from the voice signal.    
     
     
         26 . The portable telephone according to  claim 25 , wherein the ambient noise microphone is disposed on an opposite side of the portable telephone from the voice microphone.  
     
     
         27 . The portable telephone according to  claim 25 , wherein the ambient noise microphone is disposed on an opposite side and at an opposite end of the portable telephone with respect to the voice microphone.